1. Field of this Invention
This invention relates to detachable mounting ventillation for ventilator grilles and to quick mounting grilles for ventilation shafts.
2. Prior Art
U.S. Pat. No. 3,203,338 teaches the use of magnets to hold grilles in ventilator shaft openings. The use of magnets has the serious disadvantage that magnets lose their effectiveness with time and have to be replaced. Besides, magnets are relatively expensive. The magnets shown are not detachable, but are bolted or the like to the grille (which involves expensive and time-consuming adaptation of the grilles).
U.S. Pat. No. 3,220,079 discloses four - shaped flanges on the back side of a grille which snugly mate with the walls of a vent opening. The flanges are part of the grille structure, which means that special grilles must be manufactured. Same for the bent back lips on the edges of the vent opening.
U.S. Pat. No. 261,476 teaches the use of spring leafs which are screwed onto the main damper body.
U.S. Pat. No. 1,799,308 teaches self-adjusting screen door grilles which use adjustable vertical strips. Such strips are attached to the main screen door grille body on its sides by means of coil spring means which was affixed to the strips and the grill body by inserting holes drilled in both and screws inserted into the buried portions of the coil spring means.
U.S. Pat. No. 524,310 discloses the use of bent wire springs that are in essence essentially permanently affixed to the register--see FIG. 3.